The invention generally relates to a document management system and, more particularly, to a system for automatically creating and maintaining graphical depictions of documents under a universal format for convenient viewing and marking by a user.
Most computer systems include document management systems for organizing and controlling computer files containing document information. This document information is stored in a computer""s memory according to a particular format when the document is originally created. In order to access a document, application software is required for opening the file to retrieve the document to be viewed and otherwise utilized by a user""s computer. This typically must be done for each individual document. Once accessed, the document can be interactively viewed, printed and revised by a user. Different documents can be created under a large variety of formats including word processing formats for text documents, complex drawing formats for drawings such as computer aided designs (CAD) and other formats. In order to view various documents, a computer system needs to have application software that is separately developed for each type of document, often by various companies. Currently, in order for a computer to be versatile and able to open documents created under different formats, the computer must store the application software in its memory.
One conventional approach is to convert documents by implementing software algorithms to directly parse out and understand each file format under which the document was created. The resulting document can then be accessed for viewing, revising, and other functions. One problem with developing the algorithms is that many formats are difficult to access and would therefore require extensive code to interpret the individual documents. For example, many formats are proprietary to the originating application manufacturer. As a result, the algorithm designer is left to reverse engineer the details of the file contents, which is an error prone and time consuming task. To further complicate the problem, typical application file formats may undergo numerous version changes that must be taken into account by the algorithm designer. This makes the approach very labor intensive.
Also, graphics files, for example, can require two dimensional and three dimensional CAD applications, which generate complex file formats. The software code required to interpret the files would thus be voluminous and complex. To further complicate matters, data contained in the computer files are often ambiguous and ill-defined and are also uniquely interpreted by the originating application. Thus, they are difficult to duplicate. As a result, developing a program to automatically convert documents into a universal format is a difficult task.
A second approach requires a user to manually perform a conversion of every document into a neutral file format when the document is entered into the system. The documents can then be accessed by the user with a single program. This manual conversion approach, however, requires all users that enter documents into the system to have the necessary file""s application conversion software stored on the computer system. Moreover, the user needs to know how to use the conversion software properly. Furthermore, the conversion software used by the user may introduce objectionable or incorrect results if direct parsing and understanding of the file format is required. For example, if all documents are converted to a neutral file format for bit mapped images, the quality of the document will be greatly limited, especially if enlarged or reduced scales of the document are required. Accounting for quality in scaled applications can be accomplished; however, this may result in larger files when the documents are stored in the neutral file format, even in simple documents.
Therefore, there exists a need for a system that provides convenient access to documents that does not require each user to have every software application needed to access the documents that are configured under different formats. As will be seen below, the invention accomplishes this in a simple and elegant manner.
The invention provides a document management system for use in a computer system that affords convenient access to documents configured under incompatible formats. The invention allows the graphical depictions of documents under a universal format to be stored and maintained in a viewer server that can be accessed by a user on the system. This is accomplished by using a viewer server to extract a graphical image of a document while performing a print operation of a document and storing it in a separate viewer file. The system can therefore maintain files of a document under its original format and under a universal format.
The invention can be incorporated in a host processor configured to communicate with a network, where the processor contains a multitude of software applications needed to access document files configured under various formats. The original document files are managed by a file server that is accessible by the host processor and is us used by the processor to open the document files using the proper software application. A viewer server communicates with the network to generate a universal, application-neutral viewer format for configuring the original documents thereunder. This viewer format may be any arrangement of data bits that defines character information pertaining to the document, for example, vectors, angles, bitmaps of figures, etc.
The viewer server can communicate with the file server to access the original versions of the documents. The viewer server also communicates with a viewer print driver that is configured to initiate a print operation of the original document using a software application configured to access the original document according to its original format. The print driver does not necessarily print the document to a printer, but rather initiates the print operation to extract a graphical representation of the document from the data generated during the print operation. The viewer server further communicates with a viewer print monitor that is configured to monitor the print operation initiated by the viewer print driver and to respond to any user interface requests that may be generated during the printing operation. Document files containing the graphic representation are then stored in a viewer storage device that is accessible by both the viewer server and the file server, without the need for the application specific software. The resulting viewer documents can then be accessed by the host processor or any other user on the network and can be viewed and marked up by a drawing program.